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.\"	@(#)statfs.2	8.5 (Berkeley) 5/24/95
.\"
.Dd April 14, 2004
.Dt STATVFS 2
.Os
.Sh NAME
.Nm statvfs ,
.Nm statvfs1 ,
.Nm fstatvfs ,
.Nm fstatvfs1
.Nd get file system statistics
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In sys/statvfs.h
.Ft int
.Fn statvfs "const char *path" "struct statvfs *buf"
.Ft int
.Fn statvfs1 "const char *path" "struct statvfs *buf" "int flags"
.Ft int
.Fn fstatvfs "int fd" "struct statvfs *buf"
.Ft int
.Fn fstatvfs1 "int fd" "struct statvfs *buf" "int flags"
.Sh DESCRIPTION
.Fn statvfs
and
.Fn statvfs1
return information about a mounted file system.
.Fa path
is the path name of any file within the mounted file system.
.Fa buf
is a pointer to a
.Nm statvfs
structure defined in
.Xr statvfs 5 .
.Pp
.Fn fstatvfs
and
.Fn fstatvfs1
return the same information about an open file referenced by descriptor
.Fa fd .
.Pp
The
.Fn statvfs1
and
.Fn fstatvfs1
functions allow an extra
.Fa flags
argument which can be
.Dv ST_WAIT
and
.Dv ST_NOWAIT .
When
.Dv ST_NOWAIT
is specified, then only cached statistics are returned.
This can result in significant savings on non-local filesystems, where
gathering statistics involves a network communication.
.Pp
The
.Fn statvfs
and
.Fn fstatvfs
calls are equivalent to the respective
.Fn statvfs1
and
.Fn fstatvfs1
calls with
.Dv ST_WAIT
specified as the
.Fa flags
argument.
.Sh RETURN VALUES
Upon successful completion, a value of 0 is returned.
Otherwise, \-1 is returned and the global variable
.Va errno
is set to indicate the error.
.Sh ERRORS
.Fn statvfs
and
.Fn statvfs1
fail if one or more of the following are true:
.Bl -tag -width Er
.It Bq Er ENOTDIR
A component of the path prefix of
.Fa path
is not a directory.
.It Bq Er ENAMETOOLONG
The length of a component of
.Fa path
exceeds
.Brq Dv NAME_MAX
characters, or the length of
.Fa path
exceeds
.Brq Dv PATH_MAX
characters.
.It Bq Er ENOENT
The file referred to by
.Fa path
does not exist.
.It Bq Er EACCES
Search permission is denied for a component of the path prefix of
.Fa path .
.It Bq Er ELOOP
Too many symbolic links were encountered in translating
.Fa path .
.It Bq Er EFAULT
.Fa buf
or
.Fa path
points to an invalid address.
.It Bq Er EIO
An
.Tn I/O
error occurred while reading from or writing to the file system.
.El
.Pp
.Fn fstatvfs
and
.Fn fstatvfs1
fail if one or more of the following are true:
.Bl -tag -width Er
.It Bq Er EBADF
.Fa fd
is not a valid open file descriptor.
.It Bq Er EFAULT
.Fa buf
points to an invalid address.
.It Bq Er EIO
An
.Tn I/O
error occurred while reading from or writing to the file system.
.El
.Sh SEE ALSO
.Xr statvfs 5
.Sh HISTORY
The
.Fn statvfs ,
.Fn statvfs1 ,
.Fn fstatvfs ,
and
.Fn fstatvfs1
functions first appeared in
.Nx 3.0
to replace
the
.Fn statfs
family of functions which first appeared in
.Bx 4.4 .
